PTL 1 discloses an in-vehicle audiovisual (A/V) system provided with a plurality of display units in a vehicle. In this in-vehicle A/V system, in a case where the plurality of display units displays a same source, any one of the display units is given a function (priority) to preferentially operate the source. This in-vehicle A/V system prevents the display content on the display unit to which the priority is given from being impaired by the operation of the display unit to which the priority is not given.
PTL 2 discloses a device for controlling multiple monitors in a vehicle, the device being provided with a front monitor and a rear monitor in the vehicle. The front monitor is installed near a driver. The rear monitor is installed to a rear seat. According to the device for controlling multiple monitors in a vehicle, an AV device such as a digital versatile disk (DVD) player that enables viewing on the rear monitor can be safely operated through the front monitor even while the vehicle is traveling.